2 * Copyright (C) 1999,2000 Erik Walthinsen <omega@cse.ogi.edu>
3 * 2000 Wim Taymans <wim.taymans@chello.be>
4 * 2005 Wim Taymans <wim@fluendo.com>
6 * gstevent.h: Header for GstEvent subsystem
8 * This library is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU Library General Public
10 * License as published by the Free Software Foundation; either
11 * version 2 of the License, or (at your option) any later version.
13 * This library is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 * Library General Public License for more details.
18 * You should have received a copy of the GNU Library General Public
19 * License along with this library; if not, write to the
20 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
21 * Boston, MA 02111-1307, USA.
25 #ifndef __GST_EVENT_H__
26 #define __GST_EVENT_H__
28 #include <gst/gstminiobject.h>
29 #include <gst/gstformat.h>
30 #include <gst/gstobject.h>
31 #include <gst/gstclock.h>
32 #include <gst/gststructure.h>
33 #include <gst/gsttaglist.h>
39 * @GST_EVENT_TYPE_UPSTREAM: Set if the event can travel upstream.
40 * @GST_EVENT_TYPE_DOWNSTREAM: Set if the event can travel downstream.
41 * @GST_EVENT_TYPE_SERIALIZED: Set if the event should be serialized with data
43 * @GST_EVENT_TYPE_STICKY: Set if the event is sticky on the pads.
45 * #GstEventTypeFlags indicate the aspects of the different #GstEventType
46 * values. You can get the type flags of a #GstEventType with the
47 * gst_event_type_get_flags() function.
50 GST_EVENT_TYPE_UPSTREAM = 1 << 0,
51 GST_EVENT_TYPE_DOWNSTREAM = 1 << 1,
52 GST_EVENT_TYPE_SERIALIZED = 1 << 2,
53 GST_EVENT_TYPE_STICKY = 1 << 3
57 * GST_EVENT_TYPE_BOTH:
59 * The same thing as #GST_EVENT_TYPE_UPSTREAM | #GST_EVENT_TYPE_DOWNSTREAM.
61 #define GST_EVENT_TYPE_BOTH \
62 (GST_EVENT_TYPE_UPSTREAM | GST_EVENT_TYPE_DOWNSTREAM)
64 #define GST_EVENT_MAX_STICKY 16
65 #define GST_EVENT_STICKY_SHIFT 8
66 #define GST_EVENT_NUM_SHIFT (GST_EVENT_STICKY_SHIFT + 4)
69 * GST_EVENT_MAKE_TYPE:
70 * @num: the event number to create
71 * @idx: the index in the sticky array
72 * @flags: the event flags
74 * when making custom event types, use this macro with the num and
77 #define GST_EVENT_MAKE_TYPE(num,idx,flags) \
78 (((num) << GST_EVENT_NUM_SHIFT) | ((idx) << GST_EVENT_STICKY_SHIFT) | (flags))
80 #define FLAG(name) GST_EVENT_TYPE_##name
83 #define GST_EVENT_STICKY_IDX(ev) ((GST_EVENT_TYPE(ev) >> GST_EVENT_STICKY_SHIFT) & 0xf)
87 * @GST_EVENT_UNKNOWN: unknown event.
88 * @GST_EVENT_FLUSH_START: Start a flush operation. This event clears all data
89 * from the pipeline and unblock all streaming threads.
90 * @GST_EVENT_FLUSH_STOP: Stop a flush operation. This event resets the
91 * running-time of the pipeline.
92 * @GST_EVENT_EOS: End-Of-Stream. No more data is to be expected to follow
93 * without a NEWSEGMENT event.
94 * @GST_EVENT_NEWSEGMENT: A new media segment follows in the dataflow. The
95 * segment events contains information for clipping buffers and
96 * converting buffer timestamps to running-time and
98 * @GST_EVENT_TAG: A new set of metadata tags has been found in the stream.
99 * @GST_EVENT_BUFFERSIZE: Notification of buffering requirements. Currently not
101 * @GST_EVENT_SINK_MESSAGE: An event that sinks turn into a message. Used to
102 * send messages that should be emitted in sync with
105 * @GST_EVENT_QOS: A quality message. Used to indicate to upstream elements
106 * that the downstream elements should adjust their processing
108 * @GST_EVENT_SEEK: A request for a new playback position and rate.
109 * @GST_EVENT_NAVIGATION: Navigation events are usually used for communicating
110 * user requests, such as mouse or keyboard movements,
111 * to upstream elements.
112 * @GST_EVENT_LATENCY: Notification of new latency adjustment. Sinks will use
113 * the latency information to adjust their synchronisation.
115 * @GST_EVENT_STEP: A request for stepping through the media. Sinks will usually
116 * execute the step operation. Since: 0.10.24
117 * @GST_EVENT_CUSTOM_UPSTREAM: Upstream custom event
118 * @GST_EVENT_CUSTOM_DOWNSTREAM: Downstream custom event that travels in the
120 * @GST_EVENT_CUSTOM_DOWNSTREAM_OOB: Custom out-of-band downstream event.
121 * @GST_EVENT_CUSTOM_BOTH: Custom upstream or downstream event.
122 * In-band when travelling downstream.
123 * @GST_EVENT_CUSTOM_BOTH_OOB: Custom upstream or downstream out-of-band event.
125 * #GstEventType lists the standard event types that can be sent in a pipeline.
127 * The custom event types can be used for private messages between elements
128 * that can't be expressed using normal
129 * GStreamer buffer passing semantics. Custom events carry an arbitrary
131 * Specific custom events are distinguished by the name of the structure.
133 /* NOTE: keep in sync with quark registration in gstevent.c */
135 GST_EVENT_UNKNOWN = GST_EVENT_MAKE_TYPE (0, 0, 0),
136 /* bidirectional events */
137 GST_EVENT_FLUSH_START = GST_EVENT_MAKE_TYPE (1, 0, FLAG(BOTH)),
138 GST_EVENT_FLUSH_STOP = GST_EVENT_MAKE_TYPE (2, 0, FLAG(BOTH) | FLAG(SERIALIZED)),
139 /* downstream serialized events */
140 GST_EVENT_EOS = GST_EVENT_MAKE_TYPE (5, 0, FLAG(DOWNSTREAM) | FLAG(SERIALIZED) | FLAG(STICKY)),
141 GST_EVENT_NEWSEGMENT = GST_EVENT_MAKE_TYPE (6, 1, FLAG(DOWNSTREAM) | FLAG(SERIALIZED) | FLAG(STICKY)),
142 GST_EVENT_TAG = GST_EVENT_MAKE_TYPE (7, 2, FLAG(DOWNSTREAM) | FLAG(SERIALIZED) | FLAG(STICKY)),
143 GST_EVENT_BUFFERSIZE = GST_EVENT_MAKE_TYPE (8, 3, FLAG(DOWNSTREAM) | FLAG(SERIALIZED) | FLAG(STICKY)),
144 GST_EVENT_SINK_MESSAGE = GST_EVENT_MAKE_TYPE (9, 4, FLAG(DOWNSTREAM) | FLAG(SERIALIZED) | FLAG(STICKY)),
145 /* upstream events */
146 GST_EVENT_QOS = GST_EVENT_MAKE_TYPE (15, 0, FLAG(UPSTREAM)),
147 GST_EVENT_SEEK = GST_EVENT_MAKE_TYPE (16, 0, FLAG(UPSTREAM)),
148 GST_EVENT_NAVIGATION = GST_EVENT_MAKE_TYPE (17, 0, FLAG(UPSTREAM)),
149 GST_EVENT_LATENCY = GST_EVENT_MAKE_TYPE (18, 0, FLAG(UPSTREAM)),
150 GST_EVENT_STEP = GST_EVENT_MAKE_TYPE (19, 0, FLAG(UPSTREAM)),
152 /* custom events start here */
153 GST_EVENT_CUSTOM_UPSTREAM = GST_EVENT_MAKE_TYPE (32, 0, FLAG(UPSTREAM)),
154 GST_EVENT_CUSTOM_DOWNSTREAM = GST_EVENT_MAKE_TYPE (32, 0, FLAG(DOWNSTREAM) | FLAG(SERIALIZED)),
155 GST_EVENT_CUSTOM_DOWNSTREAM_OOB = GST_EVENT_MAKE_TYPE (32, 0, FLAG(DOWNSTREAM)),
156 GST_EVENT_CUSTOM_BOTH = GST_EVENT_MAKE_TYPE (32, 0, FLAG(BOTH) | FLAG(SERIALIZED)),
157 GST_EVENT_CUSTOM_BOTH_OOB = GST_EVENT_MAKE_TYPE (32, 0, FLAG(BOTH))
162 * GST_EVENT_TRACE_NAME:
164 * The name used for memory allocation tracing
166 #define GST_EVENT_TRACE_NAME "GstEvent"
168 typedef struct _GstEvent GstEvent;
170 #define GST_TYPE_EVENT (gst_event_get_type())
171 #define GST_IS_EVENT(obj) (GST_IS_MINI_OBJECT_TYPE (obj, GST_TYPE_EVENT))
172 #define GST_EVENT(obj) ((GstEvent *)(obj))
173 #define GST_EVENT_CAST(obj) ((GstEvent *)(obj))
177 * @event: the event to query
179 * Get the #GstEventType of the event.
181 #define GST_EVENT_TYPE(event) (GST_EVENT_CAST(event)->type)
184 * GST_EVENT_TYPE_NAME:
185 * @event: the event to query
187 * Get a constant string representation of the #GstEventType of the event.
189 #define GST_EVENT_TYPE_NAME(event) (gst_event_type_get_name(GST_EVENT_TYPE(event)))
192 * GST_EVENT_TIMESTAMP:
193 * @event: the event to query
195 * Get the #GstClockTime timestamp of the event. This is the time when the event
198 #define GST_EVENT_TIMESTAMP(event) (GST_EVENT_CAST(event)->timestamp)
202 * @event: the event to query
204 * The sequence number of @event.
206 #define GST_EVENT_SEQNUM(event) (GST_EVENT_CAST(event)->seqnum)
209 * GST_EVENT_IS_UPSTREAM:
210 * @ev: the event to query
212 * Check if an event can travel upstream.
214 #define GST_EVENT_IS_UPSTREAM(ev) !!(GST_EVENT_TYPE (ev) & GST_EVENT_TYPE_UPSTREAM)
216 * GST_EVENT_IS_DOWNSTREAM:
217 * @ev: the event to query
219 * Check if an event can travel downstream.
221 #define GST_EVENT_IS_DOWNSTREAM(ev) !!(GST_EVENT_TYPE (ev) & GST_EVENT_TYPE_DOWNSTREAM)
223 * GST_EVENT_IS_SERIALIZED:
224 * @ev: the event to query
226 * Check if an event is serialized with the data stream.
228 #define GST_EVENT_IS_SERIALIZED(ev) !!(GST_EVENT_TYPE (ev) & GST_EVENT_TYPE_SERIALIZED)
230 * GST_EVENT_IS_STICKY:
231 * @ev: the event to query
233 * Check if an event is sticky on the pads.
235 #define GST_EVENT_IS_STICKY(ev) !!(GST_EVENT_TYPE (ev) & GST_EVENT_TYPE_STICKY)
239 * @old_event: (inout) (transfer full): pointer to a pointer to a #GstEvent
241 * @new_event: (allow-none) (transfer none): pointer to a #GstEvent that will
242 * replace the event pointed to by @old_event.
244 * Modifies a pointer to a #GstEvent to point to a different #GstEvent. The
245 * modification is done atomically (so this is useful for ensuring thread safety
246 * in some cases), and the reference counts are updated appropriately (the old
247 * event is unreffed, the new one is reffed).
249 * Either @new_event or the #GstEvent pointed to by @old_event may be NULL.
253 #define gst_event_replace(old_event,new_event) \
254 gst_mini_object_replace ((GstMiniObject **)(old_event), GST_MINI_OBJECT_CAST (new_event))
258 * @GST_SEEK_TYPE_NONE: no change in position is required
259 * @GST_SEEK_TYPE_CUR: change relative to currently configured segment. This
260 * can't be used to seek relative to the current playback position - do a
261 * position query, calculate the desired position and then do an absolute
262 * position seek instead if that's what you want to do.
263 * @GST_SEEK_TYPE_SET: absolute position is requested
264 * @GST_SEEK_TYPE_END: relative position to duration is requested
266 * The different types of seek events. When constructing a seek event with
267 * gst_event_new_seek(), a format, a seek method and optional flags are to
268 * be provided. The seek event is then inserted into the graph with
269 * gst_pad_send_event() or gst_element_send_event().
273 GST_SEEK_TYPE_NONE = 0,
274 GST_SEEK_TYPE_CUR = 1,
275 GST_SEEK_TYPE_SET = 2,
276 GST_SEEK_TYPE_END = 3
281 * @GST_SEEK_FLAG_NONE: no flag
282 * @GST_SEEK_FLAG_FLUSH: flush pipeline
283 * @GST_SEEK_FLAG_ACCURATE: accurate position is requested, this might
284 * be considerably slower for some formats.
285 * @GST_SEEK_FLAG_KEY_UNIT: seek to the nearest keyframe. This might be
286 * faster but less accurate.
287 * @GST_SEEK_FLAG_SEGMENT: perform a segment seek.
288 * @GST_SEEK_FLAG_SKIP: when doing fast foward or fast reverse playback, allow
289 * elements to skip frames instead of generating all
290 * frames. Since 0.10.22.
292 * Flags to be used with gst_element_seek() or gst_event_new_seek(). All flags
293 * can be used together.
295 * A non flushing seek might take some time to perform as the currently
296 * playing data in the pipeline will not be cleared.
298 * An accurate seek might be slower for formats that don't have any indexes
299 * or timestamp markers in the stream. Specifying this flag might require a
300 * complete scan of the file in those cases.
302 * When performing a segment seek: after the playback of the segment completes,
303 * no EOS will be emmited by the element that performed the seek, but a
304 * #GST_MESSAGE_SEGMENT_DONE message will be posted on the bus by the element.
305 * When this message is posted, it is possible to send a new seek event to
306 * continue playback. With this seek method it is possible to perform seemless
307 * looping or simple linear editing.
309 * When doing fast forward (rate > 1.0) or fast reverse (rate < -1.0) trickmode
310 * playback, the @GST_SEEK_FLAG_SKIP flag can be used to instruct decoders
311 * and demuxers to adjust the playback rate by skipping frames. This can improve
312 * performance and decrease CPU usage because not all frames need to be decoded.
314 * Also see part-seeking.txt in the GStreamer design documentation for more
315 * details on the meaning of these flags and the behaviour expected of
316 * elements that handle them.
319 GST_SEEK_FLAG_NONE = 0,
320 GST_SEEK_FLAG_FLUSH = (1 << 0),
321 GST_SEEK_FLAG_ACCURATE = (1 << 1),
322 GST_SEEK_FLAG_KEY_UNIT = (1 << 2),
323 GST_SEEK_FLAG_SEGMENT = (1 << 3),
324 GST_SEEK_FLAG_SKIP = (1 << 4)
329 * @GST_QOS_TYPE_OVERFLOW: The QoS event type that is produced when downstream
330 * elements are producing data too quickly and the element can't keep up
331 * processing the data. Upstream should reduce their processing rate. This
332 * type is also used when buffers arrive early or in time.
333 * @GST_QOS_TYPE_UNDERFLOW: The QoS event type that is produced when downstream
334 * elements are producing data too slowly and need to speed up their processing
336 * @GST_QOS_TYPE_THROTTLE: The QoS event type that is produced when the
337 * application enabled throttling to limit the datarate.
339 * The different types of QoS events that can be given to the
340 * gst_event_new_qos_full() method.
345 GST_QOS_TYPE_OVERFLOW = 0,
346 GST_QOS_TYPE_UNDERFLOW = 1,
347 GST_QOS_TYPE_THROTTLE = 2
352 * @mini_object: the parent structure
353 * @type: the #GstEventType of the event
354 * @timestamp: the timestamp of the event
355 * @structure: the #GstStructure containing the event info.
360 GstMiniObject mini_object;
362 /*< public >*/ /* with COW */
367 GstStructure *structure;
370 gpointer _gst_reserved[GST_PADDING];
373 const gchar* gst_event_type_get_name (GstEventType type);
374 GQuark gst_event_type_to_quark (GstEventType type);
376 gst_event_type_get_flags (GstEventType type);
379 GType gst_event_get_type (void);
384 * @event: The event to refcount
386 * Increase the refcount of this event.
388 * Returns: (transfer full): @event (for convenience when doing assignments)
390 #ifdef _FOOL_GTK_DOC_
391 G_INLINE_FUNC GstEvent * gst_event_ref (GstEvent * event);
394 static inline GstEvent *
395 gst_event_ref (GstEvent * event)
397 return (GstEvent *) gst_mini_object_ref (GST_MINI_OBJECT_CAST (event));
402 * @event: (transfer full): the event to refcount
404 * Decrease the refcount of an event, freeing it if the refcount reaches 0.
406 #ifdef _FOOL_GTK_DOC_
407 G_INLINE_FUNC void gst_event_unref (GstEvent * event);
411 gst_event_unref (GstEvent * event)
413 gst_mini_object_unref (GST_MINI_OBJECT_CAST (event));
419 * @event: The event to copy
421 * Copy the event using the event specific copy function.
423 * Returns: (transfer full): the new event
425 #ifdef _FOOL_GTK_DOC_
426 G_INLINE_FUNC GstEvent * gst_event_copy (const GstEvent * event);
429 static inline GstEvent *
430 gst_event_copy (const GstEvent * event)
432 return GST_EVENT_CAST (gst_mini_object_copy (GST_MINI_OBJECT_CONST_CAST (event)));
437 GstEvent* gst_event_new_custom (GstEventType type, GstStructure *structure);
440 gst_event_get_structure (GstEvent *event);
442 gboolean gst_event_has_name (GstEvent *event, const gchar *name);
444 /* identifiers for events and messages */
445 guint32 gst_event_get_seqnum (GstEvent *event);
446 void gst_event_set_seqnum (GstEvent *event, guint32 seqnum);
449 GstEvent * gst_event_new_flush_start (void);
450 GstEvent * gst_event_new_flush_stop (void);
453 GstEvent * gst_event_new_eos (void);
455 /* newsegment events */
456 GstEvent* gst_event_new_new_segment (gboolean update, gdouble rate,
458 gint64 start, gint64 stop,
460 GstEvent* gst_event_new_new_segment_full (gboolean update, gdouble rate,
461 gdouble applied_rate,
463 gint64 start, gint64 stop,
465 void gst_event_parse_new_segment (GstEvent *event,
469 gint64 *start, gint64 *stop,
471 void gst_event_parse_new_segment_full (GstEvent *event,
474 gdouble *applied_rate,
476 gint64 *start, gint64 *stop,
480 GstEvent* gst_event_new_tag (GstTagList *taglist);
481 void gst_event_parse_tag (GstEvent *event, GstTagList **taglist);
484 GstEvent * gst_event_new_buffer_size (GstFormat format, gint64 minsize, gint64 maxsize,
486 void gst_event_parse_buffer_size (GstEvent *event, GstFormat *format, gint64 *minsize,
487 gint64 *maxsize, gboolean *async);
490 GstEvent* gst_event_new_qos (gdouble proportion, GstClockTimeDiff diff,
491 GstClockTime timestamp);
492 GstEvent* gst_event_new_qos_full (GstQOSType type, gdouble proportion,
493 GstClockTimeDiff diff, GstClockTime timestamp);
494 void gst_event_parse_qos (GstEvent *event, gdouble *proportion, GstClockTimeDiff *diff,
495 GstClockTime *timestamp);
496 void gst_event_parse_qos_full (GstEvent *event, GstQOSType *type,
497 gdouble *proportion, GstClockTimeDiff *diff,
498 GstClockTime *timestamp);
500 GstEvent* gst_event_new_seek (gdouble rate, GstFormat format, GstSeekFlags flags,
501 GstSeekType start_type, gint64 start,
502 GstSeekType stop_type, gint64 stop);
503 void gst_event_parse_seek (GstEvent *event, gdouble *rate, GstFormat *format,
505 GstSeekType *start_type, gint64 *start,
506 GstSeekType *stop_type, gint64 *stop);
507 /* navigation event */
508 GstEvent* gst_event_new_navigation (GstStructure *structure);
511 GstEvent* gst_event_new_latency (GstClockTime latency);
512 void gst_event_parse_latency (GstEvent *event, GstClockTime *latency);
515 GstEvent* gst_event_new_step (GstFormat format, guint64 amount, gdouble rate,
516 gboolean flush, gboolean intermediate);
517 void gst_event_parse_step (GstEvent *event, GstFormat *format, guint64 *amount,
518 gdouble *rate, gboolean *flush, gboolean *intermediate);
522 #endif /* __GST_EVENT_H__ */